Field of the Invention
The present invention relates to a light source including a light-emitting element, and relates to a lighting device including the light source. The lighting device here include lighting lamps, lighting bulbs, lighting tubes and so on.
Description of the Related Art
In recent years, a light-emitting diode elements (hereinafter, referred to as LED element) has been widely used in various lighting devices and electronic devices, because LED element can have a long service life, excellent drive characteristic, and an improved light-emitting efficiency even if it is small in shape. For example, conventional filament lamps have been rapidly replaced by lighting bulbs using an LED element. There are some lighting bulbs using an LED element and provided with a base including terminals that are applicable to conventional lighting fittings and/or lighting systems.
In particular, LED lamps including LED elements to acquire a desired brightness and/or including a heat-release configuration have been proposed (for reference, see JP2009-135026A, JP2010-135181A, JP2008-103112A, and WO2006-070457A).
As an example of a conventional lighting device, FIG. 9 shows an LED lamp 100L that is disclosed in JP2009-135026A. FIG. 10 shows a configuration of an LED module 100 as a conventional light source that is configured to be used in-the LED lamp 100L. The conventional LED lamp 100L includes a heat dissipator 103, an insulator 104, and a bayonet cap 102 as a base having the same structure as a conventional filament bulb. The LED lamp 100L includes the LED module 100 in which a plurality of LED elements 111 are disposed on a circuit substrate 112. The LED module 100 is configured to be mounted on an upper portion of the heat-dissipater 103 and is sealed with a spherical cover 105 made from a light-transmitting resin.
The LED module 100 includes four circuit substrates 112 that are combined as four walls that shape a frame, as shown in FIG. 10, for example. Each circuit substrate 112 is made from an insulating resin, and a plurality of LED elements 111 are mounted on outer surfaces of the frame shape formed by the four circuit substrate 112. The reference number 113 shows electrodes that are provided at inner surfaces of the frame shape formed by the four circuit substrates 112.
The LED elements 111 are configured to be driven by current supplied through the bayonet cap 102, and the spherical cover 105 covering the LED module 100 is configured to be a light-emitting portion of the LED lamp 100L.
FIG. 11 shows a module 200 that is disclosed in WO2006-070457A. The module 200 includes a laminated body 205. The laminated body 205 includes two cuboid-shaped metallic members 203a and 203b each having flat side surfaces, and an insulating spacer 202 disposed between the flat side surfaces of the metallic members 203a, 203b. The metallic member 203a as a first electrode and the metallic member 203b as a second electrode form the laminated body 205, and electronic parts 211 are mounted on the metallic members 203a and 203b. It is disclosed that LEDs can be used as the electric parts 211. The electronic part 211 mounted on the laminated body 205 has, at a lower surface of the electronic part 211, a pair of electrodes. One electrode of the electronic part 211 is electrically connected to the metallic member 203a as the first electrode, and the other electrode of the electronic part 211 is electrically connected to the metallic member 203b as the second electrode.
FIG. 12 also shows a module 300 disclosed in WO2006-070457A. The module 300 includes a laminated body 305 which has two cuboid-shaped metallic members 303a and 303b and an insulating spacer 302 disposed between the metallic member 303a and the metallic member 303b. The metallic members 303a and 303b are formed as a pair of first and second electrodes. An electronic part 311 is mounted on the first electrode and the second electrode at a peripheral side surface of the laminated body 305.
As shown in FIG. 11, the insulating spacer 202 is disposed in a linear shape at a center of the laminated body 205. As electrodes of the electronic part 211 are positioned adjacent to positions of the metallic members 203a and 303b, there is a possibility that light emitted from the electronic part 211 in a direction perpendicular to the linear-shaped insulating spacer 202 is interfered with by electrical connecting portions such as electrodes, wires, and/or solders between the electrodes of the electronic part 211 and the metallic members. If a plurality of electronic parts 211 are aligned in a straight line as shown in FIG. 11, it seems to be preferable if light emitted from the electronic parts 211 in a direction perpendicular to the straight line in which the electronic parts 211 as light-emitting elements are aligned can be efficiently used.